Hydrocarbon conversion using crystalline zeolite zsm-11 catalyst

ABSTRACT

CRYSTALLINE ZEOLITE ZSM-11 IS DISCLOSED AS A USEFUL CATALYST FOR A WIDE VARIETY OF HYDROCARBON CONVERSION PROCESSES, INCLUDING CRACKING, HYDROCRACKING, REFORMING, HYDROISOMERIZATION, OLEFIN ISOMERIZATION, HYDROGENATIONDEHYDROGENATION AND DESULFURIZATION REACTIONS, THE FAMILY OF ZSM-11 CRYSTALLINE ZEOLITES ARE CHARACTERIZED BY A CATION OF A QUARTERNARY METAL.

United States Patent 3,804,746 HYDROCARBON CONVERSION USING CRYSTAL-LINE ZEOLITE ZSM-ll CATALYST Pochen Chu, Woodbury, N.J., assignor toMobil Oil Corporation No Drawing. Original application April 23, 1970,Ser. No. 31,421, now Patent No. 3,709,979. Divided and this applicationMay 18, 1972, Ser. No. 254,800

Int. Cl. B01j 9/20; C01b 33/28; C10g 13/02 US. Cl. 208111 6 ClaimsABSTRACT OF THE DISCLOSURE Crystalline zeolite ZSM-ll is disclosed as auseful catalyst for a wide variety of hydrocarbon conversion processes,including cracking, hydrocracking, reforming, hydroisomerization, olefinisomerization, hydrogenationdehydrogenation and desulfurizationreactions. The family of ZSM-ll crystalline zeolites are characterizedby a cation of a quaternary metal.

RELATED APPLICATION This application is a divisional of Ser. No. 31,421,filed Apr. 23, 1970, now U.S. Pat. 3,709,979.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to novel crystalline zeolite compositions especially to novelcrystalline aluminosilicates, to methods for their preparation and toorganic compound conversion, especially hydrocarbon conversion,therewith.

DISCUSSION OF THE PRIOR ART Zeolitic materials, both natural andsynthetic, have been demonstrated in the past to have catalyticcapabilities for various types of hydrocarbon conversion reactions,especially catalytic cracking. Certain of these zeolitic materialscomprise ordered porous crystalline aluminosilicates having a definitecrystalline structure, as determined by X-ray diffraction, within whichthere are a large number of small cavities which are inter-connected bya series of still smaller channels or pores. These cavities and poresare precisely uniform in size within a specific zeolitic material. Sincethe dimensions of these pores are such as to accept for adsorptionmolecules of certain dimensions while rejecting those of largerdimensions, these materials have come to be known as molecular sieves,and are utilized in a variety of ways to take advantage of theadsorptive properties of these compositions.

These molecular sieves include a wide variety of positive ion-containingcrystalline aluminosilicates, both natural and synthetic. Among thesynthetic zeolites are those known as A, Y, L, D, R, S, T, Z, E, F, Q,B, X. All can generally be described as having a rigid B-dimensionalnetwork of SiO, and A10 in which the tetrahedra are crosslinked by thesharing of oxygen atoms whereby the ratio of the total aluminum andsilicon atoms to oxygen atoms is 1:2. The electrovalence of thetetrahedra containing aluminum is negatively charged and the compositionis balanced by the inclusion in the crystal structure of a cation forexample, an alkali metal or an alkaline earth metal cation. Thus, aunivalent positive sodium cation balances one negatively chargedaluminosilicate tetrahedra. Where an alkaline earth metal cation isemployed in the crystal structure of an aluminosilicate, it balances twonegatively charged aluminosilicate tetrahedra because of its doublypositive valence. Other compositions in the aluminosilicate familycontain both double positive cations, e.g., calcium and univalentpositive cations, e.g. sodium, and are prepared, for example, by baseexchanging a sodium aluminosilicate with a calcium compound solutionsuch that not all of the sodium ions are removed. By means of suchcation exchange, it has been possible to vary the size of the pores inthe given aluminosilicate by suitable selection of the particularcation. The spaces between the tetrahedra are occupied by molecules ofwater prior to dehydration.

SUMMARY OF THE INVENTION Broadly, this invention contemplates a newzeolite which can be identified, in terms of mole ratios of oxides, asfollows:

wherein M is a cation, 11 is the valence of said cation, W is selectedfrom the group consisting of aluminum and gallium, Y selected from thegroup consisting of silicon and germanium and z is from 6 to 12, saidzeolite having the X-ray diffraction pattern of Table 1 of thespecification. In the as synthesized form, the zeolite has a formula, interms of mole ratios of oxides, as follows:

wherein M is a mixture of at least one of the quaternary cations of agroup 5A element of the Periodic Table and alkali metal cations,especially sodium. The original cations can be present so that theamount of quaternary metal cations is between 10 and percent of thetotal amount of the original cations. Thus, the zeolite can be expressedby the following formula, in terms of mole ratios of oxides, as follows:

wherein W and Y have the previously assigned significance, R is an alkylor aryl group having between 1 and 7 carbon atoms, M is an alkali metalcation, X is a group 5A element, especially a metal, and X is between0.1 and 0.9. The new zeolite is designated as ZSM-ll.

The original cations can be replaced, at least in part, by ion exchangewith another cation. Preferably, the other cation is one in which thatform of the exchanged zeolite is catalytically active. Thus, theoriginal cations are exchanged into a hydrogen or hydrogen ion precursorform or a form in which the original cation has been replaced by a metalof groups 2 through 8 of the Periodic Table. Thus, it is contemplated toexchange the original cations with alkylammonium, e.g.tetramethylammonium, arylammonium, metals, ammonium and hydrogen.Preferably, preferred cations of the zeolite are those wherein, in thatcationic form, the zeolite has a good catalytic activity especially forhydrocarbon conversion. These include, in particular, hydrogen, rareearth metals, aluminum, metals of groups II and VIII of the PeriodicTable and manganese.

Catalytically-active members of the family of zeolites disclosed andclaimed herein have a definite X-ray diffraction pattern whichdistinguishes them from other zeolites. The X-ray diffraction pattern ofthe zeolite of the present invention has the following values:

, TABLE 1 Interplanar spacing d (A.):

The parenthesis around lines 3.07 and 3.00 indicate that they areseparate and distinct lines, but are often superimposed. These valueswere determined by standard techniques. The radiation was the K-alphadoublet of copper, and a Geiger counter spectrometer with a strip chartpen recorder was user. The peak heights, I, and the positions as afunction of 2 times theta, where theta is the Bragg angle, were readfrom the spectrometer chart. From these, the relative intensities, 100I/I where I is the intensity of the strongest line or peak, and d(obs.), the interplanar spacing in A, corresponding to the recordedlines, were calculated. The intensity in the table above is expressed asfollows: m.=medium, w.=weak and v.s.= very strong.

ZSM-ll is similar to ZSM-S and ZSM-8 with the notable exception thatwhereas the ZSM-5 and ZSM-8 zeolites contain a doublet at about 10.1,3.73, 3.00 and 2.01 A. interplaning spacing, ZSM-ll shows a singlet atthese values. This means that the crystal class of the ZSM-11 isdifferent from that of the other zeolites. ZSM-ll is tetragonal whereasZSM5 and ZSM-8 tend to be orthorhombic.

Ion exchange of the sodium ion with another cation reveals substantiallythe same pattern with minor shifts in interplanar spacing and variationof relative intensity.

The zeolite of the present invention can be used either in the alkalimetal form e.g. the sodium form, the ammonium form, the hydrogen form oranother univalent or multivalent cationic form.

Preferably, one or. other of the last two forms is employed. It can alsobe used in intimate combination with a hydrogenating component such astungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium,manganese, or a noble metal such as platinum or palladium where ahydrogenation-dehydrogenation function is to be performed. Suchcomponent can be exchanged into the composition, impregnated therein orphysically intimately admixed therewith. Such component can beimpregnated in or on to ZSM-ll such as, for example, by, in the case ofplatinum, treating the zeolite with a platinum metalcontaining ion.Thus, suitable platinum compounds include chloroplatinic acid, platinouschloride and various compounds containing the platinum ammine complex.

The above crystalline zeolite especially in its metal, hydrogen,ammonium, alkylammonium and arylammonium, forms can be beneficiallyconverted to another form by thermal treatment. This thermal treatmentis generally performed by heating one of these forms at a temperature ofat least 700 F. for at least 1 minute and generally not greater than 20hours. While subatmospheric pressure can be employed for the thermaltreatment, atmospheric pres sure is desired for reasons of convenience.It is preferred to perform the thermal treatment in the presence ofmoisture although moisture is not absolutely necessary. The thermaltreatment can be performed at a temperature up to about 1600 'F. atwhich temperature some decomposition begins to occur. The thermallytreated product is Relative intensity ssesses particularly useful in thecatalysis of certain hydrocarbon conversion reactions.

The new zeolite when employed either as an adsorbent or as a catalyst inone of the aforementioned processes should be dehydrated at leastpartially. This can be done by heating to a temperature in the range of200 to 600 C. in an atmosphere, such as air, nitrogen, etc. and atatmospheric, subatrnospheric or superatmospheric pressures for between 1and 48 hours. Dehydration can also be performed at room temperaturemerely by placing the ZSM- 11 catalyst in a vacuum, but a longer time isrequired to obtain a sutficient amount of dehydration.

The new zeolite can be suitably prepared by preparing a solutioncontaining (R X) O, sodium oxide, an oxide of aluminum or gallium, anoxide of silicon or germanium and water and having a composition, interms of mole ratios of oxides, falling within the following ranges:

wherein R X is a cation of a quaternary compound of an element of Group5A of the Periodic Table, W is aluminum or gallium and Y is silicon orgermanium maintaining the mixture until crystals of the zeolite areformed. Preferably, crystallization is performed under pressure in anautoclave or static bomb reactor. The temperature ranges from C.-200 C.generally, but at lower temperatures, e.g. about 100 C., crystallizationtime is longer. Thereafter, the crystals are separated from the liquidand recovered. The new zeolite is preferably formed in analuminosilicate form. The composition can be prepared utilizingmaterials which supply the appropriate oxide. Such compositions includefor an aluminosilicate, sodium aluminate, sodium silicate, silicahydrosol, silica gel, silicic acid and sodium hydroxide. The quaternarycompounds can be any element of Group SA such as nitrogen, phosphorus,arsenic, antimony or bismuth. The compound is generally expressed by thefollowing formula:

wherein X is an element of Group 5A of the Periodic Table and each R isan alkyl or aryl group having between 1 and 7 carbon atoms. Whilenormally each alkyl or aryl group will be the same, it is not necessarythat each group have the same number of carbon atoms in the chain. Theoxide of the quaternary metal compound is generally supplied byintroducing into the reaction mixture a composition such as tetramethyl,tetraethyl, tetrapropyl or terabutyl metal hydroxide or chloride. Inpreparing an ammonium species, tetrabutyl ammonium chloride or hydroxideis especially useful. In preparing the phosphonium species of thezeolite, tetrabutylphosphonium chloride is particularly desirable as ameans of incorporating the quaternary metal compound in the zeolite. Theother metals of Group SA behave similarly and thus zeolites containingthe same can be prepared by the same manipulative procedure substitutingthe other Group SA metal for phosphorus. It should be realized that theoxide can be supplied for more than one source. The reaction mixture canbe prepared either batchwise or continuously.

claimed herein can be base exchanged to remove-the so-' dium cations bysuch ions as hydrogen (from acids), ammonium, alkylammonium andarylammonium including RNH R NH' R2NH3+ and R N+ where R is alkyl oraryl, provided that steric hindrance does not prevent the cations fromentering the cage and cavity structure of the new zeolite composition.The hydrogen form of the.

new zeolite is prepared, for example, by base exchanging the sodium formwith, say, ammonium chloride or hydroxide whereby the ammonium ion issubstituted for the sodium ion. The composition is then: calcined at atemperature of, say, 1000 .F. causing evolution of ammonia and retentionof a proton in the composition. Other replacing cations include cationsof the metals of the Periodic Table, especially metals other thansodium, especially metals of Group II, e.g., zinc and Group VIII of thePeriodic Table and rare earth metals and manganese.

Ion exchange of the zeolite can be accomplished conventionally, as bypacking the zeolite in the form of beds in a series of vertical columnsand successively passing through the beds a water solution of a solublesalt of the cation to be introduced into the zeolite; and then to changethe flow from the first bed to a succeeding one as the zeolite in thefirst bed becomes ion exchanged to the desired extent. Aqueous solutionsof mixtures of materials to replace the sodium can be employed. Forinstance, if desired, one can exchange the sodium with a solutioncontaining a number of rare earth metals suitably in the chloride form.Thus, a rare earth chloride solution commercially available can be usedto replace substantially all of the sodium in the as synthesized form ofthe zeolite. This commercially available rare earth chloride solutioncontains chlorides of rare earth mixture having the relative compositioncerium (as CeO 48 percent by weight, lanthanum (as 1.21 24 percent byweight, praseodymium (as mo 5 percent by weight, neodymium (as Nd,o, 17percent by weight, samarium (as Sm O 3 percent by weight, gadolinium (asGd O' 2 percent by weight, and other rare earth oxides 0.8 percent byweight. Didymium chloride is also a mixture of rare earth chlorides, buthaving a lower cerium content. It consists of the following rare earthsdetermined as oxides: lanthanum 45-65 percent by weight, cerium 1-2percent by weight, praseodymium 9-10 percent by weight, neodymium 32-33percent by weight, samarium 5-7 percent by weight, gadolinium 3-4percent by weight, yttrium 0.4 percent by weight, and other rare earths1-2 percent by weight. It is to be understood that other mixtures ofrare earths are also applicable for the preparation of the novelcompositions of this invention, although lanthanum, neodymium,praseodymium, samarium and gadolinium as well as mixtures of rare earthcations containing a predominant amount of one or more of the abovecations.

A wide variety of acidic compounds can be employed to prepare thehydrogen form of the new. catalyst. Theseacidic compounds, which are asource of hydrogen ions,-

include both inorganic and organic acids,

The hydrogen form of the new zeolite can be prepared generally by twomethods. The first involves direct ion exchange employing an acid.Suitable acids include both inorganic acids and organic acids. Typicalinorganic acids which can be employed include hydrochloric acid,hypochlorous acid, sulfuric acid, sulfurous acid, hydrosulfuric-Representative suitable acids include acetic acid, trichloroacetic acid,bromoacetic, citric acids, maleic, fumaric, itaconic acid, phenylacetic,benzene sulfonic acid and methane-sulfonic and the like.

The second method for preparing a hydrogen form involves first preparingan ammonium for other hydrogen ion precursor form by base exchange andthen calcining to cause evolution of the ammonia leaving a hydrogen ionremaining on the zeolite. Suitable compounds for preparing the hydrogenion precursor form include ammonium compounds such as ammonium chloride,ammonium bromide, ammonium iodide, ammonium bicarbonate, ammoniumsulfate, ammonium citrate, ammonium borate, ammonium palmatate and thelike. Still other ammonium compounds which can be employed includequaternary ammonium compounds such as tetramethylammoniumhydroxide andtrimethylammonium chloride.

The wide variety of metallic compounds can be employed with facility asa source of metallic cations include both inorganic and organic saltsfor the metals of Groups I through VIII of the Periodic Table.

While water will ordinarily be the solvent in the base exchangesolutions employed, it is contemplated that other solvents, althoughgenerally less preferred, can be used in which case it will be realizedthat the above list of exchange compounds can be expanded. Thus, inaddition to an aqueous solution, alcohol solutions and the like of theexchange compounds can be employed in producing the exchanged catalystof the present invention. Generally, the alkali metal content is reducedto less than 4 percent by weight and preferably less than 1 weightpercent. When the exchanged zeolite is prepared, it is generally,thereafter, treated with a suitable solvent, e.g. water, to wash out anyof the anions which may have become temporarily entrained or caught inthe pores or cavities of the crystalline composition.

As indicated above, the aluminosilicates prepared by the instantinvention are formed in a wide variety of particular sizes. Generallyspeaking, the particles can be in the form of a powder, a granule, or amolded product, such as an extrudate having particle size sufficient topass through a 2 mesh (Tyler) screen and be retained on a 400 mesh(Tyler) screen. In cases where the catalyst is molded, such asextrusion, the aluminosilicate can be extruded before drying or dried orpartially dried and then extruded.

'In the case of many catalysts, it is desired to incorporate the newzeolite with another material resistant to the temperatures and otherconditions employed inorganic conversion processes. Such materialsinclude active and inactive materials and synthetic or naturallyoccurring zeolites as well as inorganic materials such as clays, silicaand/or metal oxides. The latter may be either naturally occurring or inthe form of gelatinous precipitates or gels including mixtures of silicaand metal oxides. Use of a material in conjunction with the new zeolite,i.e. combined therewith which is active, tends to improve the conversionand/or selectivity of the catalyst in certain organic conversionprocesses. Inactive materials suitably serve as diluents to control theamount of conversion in a given process so that products can be obtainedeconomically and orderly without employing other means for controllingthe rate of reaction. Normally, zeolite materials have been incorporatedinto naturally-occurring clays, e.g. bentonite and kaolin, to improvethe crush strength of the catalyst under commercial operatingconditions. These materials, i.e. clays, oxides, etc., function asbinders for the catalyst. It is desirable to provide a catalyst havinggood crush strength because in a petroleum refinery the catalyst isoften subjected to rough handling, which tends to break the catalystdown into powder-like materials which cause problems in processing.These clay binders have been employed normally only for the purpose ofimproving the crush strength of the catalyst.

Naturally-occurring clays which can be composited with the new zeoliteZSM-ll catalyst include the montmorillonite and kaolin family, whichfamilies include the sub-bentonites, and the kaolines commonly known: asDixie McNamee-Georgia and Florida clays or others in which the mainmineral constituent is halloysite, kaolinite, dickite, nacrite, oranauxite. Such clays can be used in the raw state as originally mined orinitially subjected to calcination, acid treatment or chemicalmodification. Binders useful for compositing with the ZSM-ll catalystalso include inorganic oxides, notably alumina.

In addition to the foregoing materials, the ZSM-ll catalyst can becomposited with a porous matrix material such as silica-alumina,silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia,silica-titania as well as ternary compositions such assilica-alumina-thoria, silica-aluminazirconia, silica-alumina-magnesiaand silica-magneiazirconia. The matrix can be in the form of a cogel.The relative proportions of finely divided crystalline aluminosilicateZSM-ll and inorganic oxide gel matrix vary widely with the crystallinealuminosilicate content ranging from about 1 to about 90 percent byweight and more usually, particularly when the composite is prepared inthe form of beads, in the range of about 2 to about 50 percent by Weightof the composite.

Employing the catalyst of this invention, containing a hyrogenationcomponent, heavy petroleum residual stocks, cycle stocks, and otherhydrocrackable charge stocks can be hydrocracked at temperatures between400 F. and 825 F. using molar ratios of hydrogen to hydrocarbon chargein the range between 2 and 80. The pressure employed will vary betweenand 2,500 p.s.i.g. and the liquid hourly space velocity between 0.1 and10.

Employing the catalyst of this invention for catalytic cracking,hydrocrabon cracking stocks can be cracked at a liquid hourly spacevelocity between about 0.5 and 50, a temperature between about 550 F.and 1100 F., a pressure between about subatmospheric and several hundredatmospheres.

Employing a catalytically active form of a member of the family ofzeolites of this invention containing a hydrogenation component,reforming stocks can be reformed employing a temperature between 700 F.and 1000 F. The pressure can be between 100 and 1000 p.s.i.g., but ispreferably between 200 and 700 p.s.i. g. The liquid hourly spacevelocity is generally between 0.1 and 10, preferably between 0.5 and 4and the hydrogen to hydrocarbon mole ratio is generally between 1 and20, preferably between 4 and 12.

The catalyst can also be used for hydroisomerization of normal paraflinswhen provided with a hydrogenation component, e.g. platinum.Hydroisomerization is carried out at a temperature between 200 to 700F., preferably 300 to 550 F., with a liquid hourly space velocitybetween 0.01 and 2, preferably between 0.25 and 0.50 employing hydrogensuch that the hydrogen to hydrocarbon mole ratio is between 1:1 and 5:1.Additionally, the catalyst can be used for olefin isomerizationemploying temperatures between 30 F. and 500 F.

Other reactions which can be accomplished employing the catalyst of thisinvention containing a metal, e.g. platinum, includehydrogenation-dehydrogenation reactions and desulfurization reactions.

In order to more fully illustrate the nature of the invention and thematter of practicing the same, the-following examples are presented:

EXAMPLE 1 90 grams of sodium silicate, one gram of sodium aluminate and168 grams of H 0 were mixed in a blender. Approximately 9.9 grams ofsulfuric acid (98 percent H SO was added to the mixture to adjust the pHbelow 10. Then 11 grams of tetra butyl phosphonium chloride in 152 gramsof H 0 was added slowly. The mixture turned into an opaque gel. The gelwas heated to 120 A1 0 1.00 510: 48.00 Nago (TBP) O 1 .066

1 Tetra butyl phosphonium cation calculated from P analysis.

The product had the following X-ray diffraction pattern wherein I/Iindicates the relative intensity:

, TABLE 3 *Interplanar spacing d (A.): Relative intensity I/I 11.19 2710.07 23 7.50 2 7.25 1 7.11 1 6.73 3 6.42 2 6.33 2 6.09 3 6.03 5 5.75 25.61 5 5.16 1 5.03. 3 4.62 4 4.48 1 4.37 9 4.28 2 4.08 2 4.00 4 3.86 13.73 39 3.68 5 3.49 6 3.41 3 3.35 5 3.27 l 3.19 1 3.14 21 3.07 6 3.00 102.87 2 Y 2.80 1 2.62 3 2.56 1 2.51 2 2.50 4 2.46 1 2.42 2 2.40 2 2.35 22.28 1 2.24 1 2.21 1 2.18 1 2.14 1 2.12 2 2.09 2 2.08 2 2.01 21 1.99 21.97 4 1.93 5 1.88 7 1.85 1 1.82 1 1.78 3 1.76 2 1.74 1 1.72 1

9 TABLE 3Continued The final gel mixture in Example 1 was heated in asteam bath (-220 F.) for 9 days. The product has the same X-raydiffraction pattern and chemical analysis as the product of Example 1.

EXAMPLE 3 Example 1 was repeated except that the preheat step waseliminated. The mixture crystallized after heating at 300 F. in anautoclave for 66 hours. The product gave the X-ray pattern of Table 1.Chemical analysis is as follows, in terms of mole ratios of oxides:

A1 1.00 SiO 50.0 Na O 0.36 (TBP) O 1 0.69

1 Tetrabutyl phosphonium cation calculated from P analysis.

EXAMPLE 4 Different phosphonium compounds were used. 50 grams of sodiumsilicate and one gram of sodium alumin a t and 108 grams of water weremixed in a blender. 2.5 grams of H 50 was added. Then 6.5 grams ofbenzyl triphenyl phosphonium chloride in 40 grams of H 0 was addedslowly. Crystallization was carried out in an autoclave at 300 F. for 4days. The product gave the X-ray pattern of Table 1 above.

EXAMPLE 5 Different forms of silica can be used as the silicon source ofthis invention. The following components were mixed together in ablender in the following sequence:

(1) 88 grams of fine colloidal SiO (30 percent) (2) 1.2 grams of sodiumaluminate (3) 11 grams of tetra butyl phosphonium chloride (4) 250 gramsof H 0 (5) 2.4 grams of NaOH.

The mixture appeared as a very dilute colloidal suspension.Crystallization was conducted at 500 F. for 67 hours. The product gavethe X-ray pattern of Table 1.

EXAMPLE 6 This zeolite can be used as absorbent and catalyst in isoriginal form (sodium-TBP form), ion exchanged: form, e.g. exchangedzinc form and/or calcined ammo-L nium form. The latter form was preparedby exchanging;

20 grams of the product of Example 3 with 200 ml. of]

1 N NH Cl solution at 180 F. for four l-hour periods. The exchangedzeolite was then washed chloride free and dried at 210 F. Thereafter, itwas calcined in a muffle at 1000 F. for 1 hour. The structure of thezeolite crystal remained unchanged after calcination as shown by the X-ray pattern.

EXAMPLE 7 The calcined ammonium form of Example 6 has shown goodactivity in the cracking of n-hexane. The results have shown that at 900F. the n-C H conversion were 24.2 and 31.8 percent by weight at 5minutes and 25 minutes respectively. The alpha values determined inaccordance with the method described by P. B. Weisz and I. N. Miale inJournal of Catalysis, vol. 4, No. 4, August 1965, pp. 527-9 were 39 and54 at 5 minutes and 25 minutes.

ZSM-ll appears to have an effective free aperture for the portualscontrolling access to the intracrystalline void volume of about 7 A.Under test conditions, m-xylene, m-diethyl benzene, 2-methyl naphthaleneand 1,2, 4-trimethyl-benzene were selectively sorbed while o-diethylbenzene and l-methyl naphthalene were excluded. This indicates thatZSM-ll is effective as a shape selective catalyst in preferentiallysorbing one isomer from another. A summary of the shape selectivesorption properties of the hydrogen form of ZSM-ll is set forth below.

Examination of the sorption properties of a sample of as synthesizedZSM-ll activated at 400 C. in He shows that almost all of theintracrystalline void volume in ZSM-ll is initially occupied by the P(CH ions. The intracrystalline void volume defined by the PR ionsassumingan ionic diameter of 9.8 A.--is about 0.12 ml./ g. The weight lossesoccurring above 400 C. in 0 and 500 C. in the He9.6 and 10.3 weightpercent respectively--agree closely with that calculated for completedecomposition of the P(C H ions, namely 9.9 weight percent.

Zeolite ZSM-ll activated at 600 C. in He exhibits intracrystallinesorption of cyclohexane (critical diameter about 6 A.) at 25C. and 20mm. Hg. Access to the main pore system in ZSM-ll apparently occursthrough relatively large windows, probably comprised of at least 12tetrahedra. 2,2-dimethylbutane was sorbed at a somewhat slower rate thancyclohexane. The free void volume defined by cyclohexane in ZSM-ll issimilar to that formerly occupied by the P(C H ions-namely 0.09 ml./ g.and 0.12 ml./g., respectively. The intracrystalline void volumeavailable to n-C H (critical diameter about 4.6 A.) is much larger thanthat defined by cyclohexane-- 0.18 and 0.09 ml./g., respectively.Intracrystalline molecular sieving between n-C H and cyclohexane showsthe presence of a dual pore system in which access to the small poresystem is probably controlled by 8-membered rings such as found ingmelinite cages. The apparent free void volume defined by H O isconsiderably lower than that defined by n-C Hi 0.l1 and 0.18 ml./g.,respectively. In ZSM-ll the fractional void volume defined by H O isequivalent to that defined by cyclohexane. One possible explanation isthat H O under the existing experimental conditions (25 C., 12 mm.) didnot penetrate the secondary small-pore system present in highsilicazeolites such as ZSM-l 1.

From the solutions, a zeolite was prepared. Solution A was added toSolution B and the two were mixed together.

1 l Thereafter, Solution C was added and mixed for 10 minutes. It wastransferred to a polypropylene jar and maintained for 23 days at 212 F.until a product crystallized. The composition of the reaction mixture,in terms of mole ratios, was as follows:

Tetrabutyiammonlum ------=0.489 Tetrabutylammonium plus sodium Theproduct was filtered, washed with water and dried at 230 F. It had anX-ray diffraction pattern set forth in Table 4. After it was calcinedfor 24 hours at 1000 F. its sorption properties were determined. It wasfound to sorb 7.3 weight percent cyclohexane, 8.9 weight percent normalhexane and 7.0 weight percent water under the sorption conditions abovereported. Chemical analysis of the product showed the SiO /Al O ratio to73.

TABLE 4 Example 8 Example 8 calcined for 20 hr. at 550 0.

(IA: III M. III

11. 19 29 11. 19 B 10. 10 23 10. 10 54 9. 36 58 7. 50 3 7. 47 2 0. 76 36. 44 2 6. 42 3 6. 03 5 6. 01 16 5. 61 4 5. 57 0 5. i5 1 5.01 e 4. 02 54. 61 4 4. 39 9 4. 37 0 3. 87 100 3. 86 100 3. 74 d3 3. 73 33 3. 69 1 3.69 1 3. 50 5 3. 49 0 3. 36 8 3. 34 7 3. 11 3 3. 07 0 3. 06 7 3. 00 11 2.98 12 2. 88 3 2. 80 1 2. 80 2 2. 79 1 2. 62 5 2. 62 4 2. 50 7 2. 50 4 2.36 3 2. 34 4 2. 19 1 2. 01 21 2. 01 0 1. 88 6 1. 87 2 1. 78 2 l. 77 1 1.68 6 1. 60 2 EXAMPLE 9 The product from Example 8 was calcined for 10hours at 1000 F. and then contacted, while stirring, with NH CI solution(12 grams NH CI dissolved in 228 cc. H O) at room temperature for onehour which was followed by filtering. This exchange was repeated twicemore. It was then water washed free of chloride ions and dried at 230 F.The dried crystalline aluminosilicate was pelleted and sized 4-10 mesh(U.S. sieve) and recalcined by heating at 1000 F. for 10 hours. Thecalcined catalyst was evaluated for catalytic cracking conditions at 20LHSV, 0.3 catalyst/oil ratio and 875 F. The charge was an Amal gas oilhaving a boiling range of 650-l000 F. and a pour point of 100 F.

Catalytic results for the cracking of the Amal gas oil are summarized inthe following table:

TABLE 5 Conversion, vol. percent: 49.8 Cs+ gasoline, vol. percent: 27.4Total Crs vol. percent: 15.9

D gas, wt. percent: 11.8

00 e, wt. percent: 0.5

H, wt. percent: 0.05

(Jr-Ci distribution Product fractions: Pour point, F. 5

The foregoing demonstrates that the ZSM-ll catalyst of the presentinvention, prepared either employing tetrabutylammonium or a tetrabutylmetal compound is, in a catalytic form, useful for catalytic dewaxing toimprove the octane value of charge stocks so cracked. By cracking normalparafiinic contents without cracking isoparaffins, the resultant liquideflluent has a higher octane value.

EXAMPLE 10 Example 8 was repeated except that the amount of sodiumaluminate was 3.0 grams, the amount of sodium hydroxide 15.0 grams andthe amount of water 640 grams. The amount of colloidal silica was 375grams and tetrabutylammonium bromide was employed. The amount oftetrabutylammonium bromide was 75 grams. The crystalline product whichwas crystallized in a polypropylene jar by subjecting it to 212 F. for23 days was found to have an X-ray diffraction pattern substantiallythat of Table 1 above.

I claim:

1. A method of converting a hydrocarbon charge which comprisescontacting a convertible hydrocarbon charge under hydrocarbon conversionconditions with a catalytically-active form of a crystallinealuminosilicate zeolite having a composition in terms of mole ratios ofoxides as follows:

0.9i0.3M O:Al O :20 to SlOziZHzO wherein M is at least one cation, n isthe valence of said cations, and z is from 6 to 12, said zeolitebelonging to the tetragonal system and having the X-ray diffractionvalues set forth in Table l of the specification, with a singlet atvalues 10.1, 3.73, 3.00 and 2.01, and products of thermal treatment ofsaid aluminosilicate, said thermal treatment comprising heating the sameat a temperature of at least about 700 F. up to about 1600" F. for atleast one minute.

2. A method of converting a hydrocarbon charge which comprisescontacting a convertible hydrocarbon charge under hydrocarbon conversionconditions with a catalytically-active form of a crystallinealuminosilicate zeolite having a composition in terms of mole ratios ofoxides as follows:

wherein M is hydrogen, ammonium, or a metal of Groups II-VIII of thePeriodic Table or mixtures thereof, n is the valence of said cations,and z is from 6 to 12, said zeolite belonging to the tetragonal systemand having the X-ray diffraction values set forth in Table 1 of thespecification, with a singlet at values 10.1, 3.73, 3.00 and 2.01, andproducts of thermal treatment of said aluminosilicate, said thermaltreatment comprising heating the same at a temperature of at least abou700 F. up to about 1600 F. for at least one minute.

3. A method of cracking a hydrocarbon cracking stock comprisingmolecules which can be cracked to molecules of lower average molecularweight which comprise contacting said hydrocarbon cracking stock with acatalytically-active form of the zeolite of claim 1 at a temperaturebetween 550 F. and 1100 F., a pressure between subatmospheric andseveral hundred atmospheres and a liquid hourly space velocity between0.5 and 50.

4. A method of cracking a hydrocarbon cracking stock comprisingmolecules which can be cracked to molecules of lower average molecularweight which comprise contacting said hydrocarbon cracking stock with acatalytically-active form of the zeolite of claim 2 at a temperaturebetween 550 F. and 1100 F., a pressure between subatmospheric andseveral hundred atmospheres and a liquid hourly space velocity between0.5 and 50.

5. A method of hydrocracking a hydrocrackable hydrocarbon stockcomprising molecules which can be cracked in the presence of hydrogen toyield products having lower average molecular weight which comprisecontacting said hydrocracking stock with a catalytically-active term ofthe zeolite composition of claim 1 containing a hydrogena- 14 tioncomponent at temperatures between 400 F. and 825 F. in the presence ofhydrogen such that the molar ratio of hydrogen to hydrocarbon is in therange bet-ween 2 and 80, under a pressure between 10 and 2500 p.s.i.g.at a liquid hourly space velocity between 0.1 and 10.

6. A method of hydrocracking a hydrocrackable hydrocarbon stockcomprising molecules which can be cracked in the presence of hydrogen toyield products having lower average molecular weight which comprisecontacting said hydrocracking stock with a catalytically-active form ofthe zeolite composition of claim 2 containing a hydrogenation componentat temperatures between 400 F. and 825 F. in the presence of hydrogensuch that the molar ratio of hydrogen to hydrocarbon is in the rangebetween 2 and 80, under a pressure between 10 and 2500 p.s.i.g. at aliquid hourly space velocity between 0.1 and 10.

References Cited UNITED STATES PATENTS 2,882,243 4/ 1959 Milton 423-3293,054,657 9/1962 Breck 423-329 3,216,789 11/1965 Breck et a1 423-3293,248,170 4/ 1966 Kvetinskas 423-328 3,014,871 12/1961 Fulton et a1 .Q252-49] 3,306,922 2/ 1967 Barrer et al 260-448 R 3,308,069 3/1967Wadlinger et a1. 252-455 Z 3,314,752 4/1967 Kerr 252-430 3,431,2193/1969 Argaver 252-455 Z 3,459,676 8/ 1969 Kerr X423-329 DELBERT E.GANTZ, Primary Examiner G. E. SCHMITKONS, Assistant Examiner US. Cl.X.R.

208-DIG. 2, 120, 209; 252-455 Z

